


Swim Away

by PageOne_2020



Category: Free!
Genre: Fishy experiments, M/M, Post-Canon, Rei is a scientist, merman AU with a twist
Language: English
Status: In-Progress
Published: 2021-02-27
Updated: 2021-03-02
Packaged: 2021-03-18 08:27:24
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 10,073
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29731101
Author URL: https://archiveofourown.org/users/PageOne_2020/pseuds/PageOne_2020
Summary: The Iwatobi crew is brought to Rei's University lab for a private viewing of his senior thesis project.  Everything is going fine until a seemingly-innocuous lab accident leaves Haru with more than just a sneak-peek of some lizard experiments.  Soon, he's permanently moved into his bathtub, eating mackerel raw, and trying to keep his scales from drying out. Good thing Rin's around to hov- er, help.Rei has his work cut out for him.
Relationships: Matsuoka Rin/Nanase Haruka
Comments: 3
Kudos: 9





	1. Chapter 1

**Notes for the Chapter:**

> Basically I got on the mermaid AU bandwagon via non-scientific means, or rather, science fiction means.

“Oi, Haru, move over, will ya?”

“I’m trying,” he snapped, something banging into his hip – probably a table – hard enough to leave a bruise.

“Who the hell leaves a lab like this, anyway? You see a light switch?”

“You find it.”

“I’m trying,” Rin grit out over the sound of his hand slapping against drywall.

Rei was a Senior at Tokyo University and had been working on a graduation project for the past three years. The project had remained a mystery in all that time, but Rei had wanted to show them his work before he turned in the thesis report. And, presumably, show off his lab, as this was their first visit to the equally mysterious room on the fifth floor of the biology building.

Which was how he found himself stumbling around a dark room full of hazardous chemicals with Rin Matsuoka, fellow rival/teammate on the Japan National Swim Team.

Another bang against something that clanked, forcing him to freeze before something fell and shattered, probably on his toes.

And, yes, Haru knew Rei had a tendency to be absent-minded. But in all fairness, he was usually on time. Hell, he and Rin weren’t even early – they were actually seven minutes late. Yet, the place was empty, the lights were off, and there was no sign of their friends.

For the first time, Haru wondered if Nagisa had really acquired the lab key by legitimate means.

“Found it,” Rin announced unnecessarily as the room was flooded with white, fluorescent light.

The sudden illumination made Haru blink rapidly so his eyes would adjust. The place was… well, it was obvious Rei was sharing the lab benches with someone, because the Rei they knew would never a lab space in such a shambles. There were two computer terminals beneath the window and one on the table Haru had run into; only one of them was free of sticky notes, scribbled notepads, and random lab utensils on the bench. Haru made his way over, even more sure the clean space by the window was Rei’s station when he saw the butterfly-stenciled notepad neatly to the side.

“Which one do you think is Rei’s?” Rin asked.

Haru whirred around to find him examining a shelf of experiments on the closest wall. The shelf wasn’t the only assortment of odd-colored, glass beakers – a hardtop bench lined the wall to Haru’s left, various jars crammed into every available space. The messier tenants had left the benchtop beneath it full, beakers of funny colors and opaque glasses with hazard labels left for all to see.

“Don’t touch anything,” Haru stated as Rin started twisting beakers around for labels.

“Yeah, probably not a good idea,” he agreed, withdrawing his hands, slipping them into his jean pockets to remove temptation. Rin, however, wasn’t made to sit around waiting for people, and he soon found something else to start poking his nose into.

“Rin.”

“What?” he questioned innocently, contrary to the not-so innocent way he was opening file cabinets and unashamedly peeking through their contents. “I’m just making sure they don’t have Rei slaving away on somethin’ stupid like dirt cultures.”

Haru rolled his eyes, deciding against snooping to watch traffic through the lab window. It was a Friday evening after classes, so the campus was emptier than usual, sun setting over the city skyline and painting everything a peach tint.

“Wow, look at that!”

It was interesting watching life in the streets outside. He could see the figures of chatting students below, headed off to karaoke or an early dinner. Maybe even headed home to-

“I can’t believe they’re doin’ this stuff here. I mean…”

Haru clenched his jaw, determined to keep his gaze on the street. He didn’t snoop. He wouldn’t snoop. That was just…

…

Who was he kidding?

Haru gave into the temptation, head down and a little annoyed with Rin for tempting him to daredevil stuff he didn’t want to do in the first place. As soon as he reached his side, given away by squeaking sneakers on the linoleum, Rin shot him a knowing smirk before going back to the papers in hand.

“Look at this – these are trials for cancer immunotherapy,” Rin explained, flashing a file folder in his direction.

“Isn’t that dangerous?” Haru asked, curiosity getting the better of him as he scanned the fine-line printing. The paper was in English, so he couldn’t catch most of it (well, any of it, actually), but the tables and figures looked telling.

“Um, sort of,” Rin explained, flipping pages. “I’ve heard of this. It’s, like, targeted diagnostics. They can use antibodies to label the cancer cells, and the immune cells go after it like it’s an infection.” He put the file back, brows furrowed in concentration. “I didn’t know they were doing any of this out of your university, though.”

“Former university,” Haru corrected on instinct.

Rin shrugged, already looking for the next thing to read. “Just because you graduated from here last year doesn’t mean it still isn’t your school, Haru. Kind of like… Samezuka will always be the place I created my first relay that made it to regionals. No matter what other relay I race, that'll always be there.” 

"Is that like your Australian University?"

A flip as Rin thumbed through some more files. "Yeah, I guess. I mean, I'm living here in Tokyo and I'm part of the national team now, but... it'll always be part of me. It was where I got a foot in my professional career and learned so much. It's kind of like you and this place." Rin shot him a glance. Haru didn’t say anything, and he didn’t seem to expect him to; they continued browsing.

The cancer study appeared to be the last of interest in the file cabinet, and Rin wandered over to a glass-encased cabinet beside the door. It was five rows high and full of glass jars with various fluids. Also locked, but there was a tray of vials missing.

Rin, curiosity piqued yet again, looked around until he spotted the vials. They were on the tabletop in the center of the room, standing separate from the other jars like pawns marching alone across a chess board.

“What’s in there?” he asked, peering at them with interest.

Haru didn’t have an answer, but upon stepping closer, he could admit the glass tubes looked kind of strange. Two of them were ruby-colored and stoppered, and the third was a kind of luminescent liquid. And… wait, was it-

“Is that sparkling?”

Haru leaned closer in kind, the two bent over the three glass tubes. The third one was indeed sparkling, like an electric eel shimmering beneath a cerulean surface. It was kind of pretty, actually, but a little freaky for a biology lab.

Before he could stop him, Rin flicked the vial. And the substance inside… it was viscous, thicker than water. More like oil.

“Well, shit. Guess I should have gone into chemistry.” Haru gave him a flat look and Rin shrugged. “What? I’m smart enough. I could cut it.”

_As if. You wouldn’t do anything to take time from your swimming._

Rin, amazingly, seemed to understand his blank stare. Only, he smirked, choosing to interpret it differently. “But then, what would the swim team to do without me?”

Haru resisted an eye-roll. Barely.

Before they – in other words, Rin – could find anything else probably off-limits, steps sounded outside the door. Both adults turned their heads in time to watch Makoto come bursting into the lab, panting heavily, and clutching his messenger bag tight to his chest.

“Did I- Am I late?”

Rin leaned against the table, arms crossed to face their friend. “Yeah, man, but so’s-“

“Agh, Nagisa! Please refrain from touching those cultures. I have them on donation from the biology department, and I really don’t need-“

“Relax, Rei! They’re just a bunch of cells. How much harm can we do? Look at them, all happy in their solutions~”

The familiar duo came bursting in so fast they almost rear-ended Makoto with a cart they were pushing. It was only thanks to the reflexes honed by years of caring for two twins that had him scrambling out of the way in time.

The cart Rei pushed contained several stacks of peach-colored petri dishes. Nagisa, as usual, came trotting in chattering and trying to reach whichever ones were closest. Rei, decked out in the bleached lab coat and gloves, gave him a stern lecture when hands so much as made a movement, siting something about contaminating cultures with bacteria and killing off his samples.

“And another thing – flip-flops and shorts are not permitted in the lab space,” he continued, wheedling the cart over to the center table. “if any chemicals were to spill, you’d be-“

“But they’re not going to spill!” Nagisa countered, completely unconcerned over potential dangers. “You know what you’re doing, Rei. Nothing in here would ever hurt us.”

Rei did that odd freezing-blinking thing he did whenever someone paid him a compliment, quickly adjusting his lenses to hide any potentially incriminating blush. “While I appreciate the confidence, Nagisa, I think it would be much better if you abided by lab safety rules. In the future, I insist upon closed-toed shoes, long pants, and no jewelry. Accidents do happen, and they could injure you grievously.”

“Hey guys,” Makoto was quick to step in, sweet smile firmly in place. “why don’t we put that aside for now. Rei, wasn’t there something you wanted to show us?”

Rei practically jumped, as if noticing for the first time his lab was already occupied. “Makoto, Haru, Rin… Welcome. I apologize for our tardiness – I had to go to the other end of campus to get these, but the student was delayed and it took longer than expected. My apologies.”

“No worries, man,” Rin grinned, slapping him on the shoulder in welcome. “What’d ya bring us down here for?”

Rei seemed to waffle but decided to let the situation go in favor of more pressing interests. “As you both may know, I’ve been working on a superior chemical design to better allow for genetic modification and insertion of genes into a pre-existing genome, and we’ve been running tests on lizards from the southern islands. I’ve been comparing the different techniques using variations of…”

At that point, Rei disappeared into a separate door behind the far wall that Haru had failed to notice, since it was tucked in the shadow of a large refrigerator. Whatever he kept explaining couldn’t be made out over the hum of said appliance, although they could make out the sounds of metal clanking and something being moved. Which was probably fine, because what he'd been saying in the first place made absolutely no sense to those assembled, but Rei didn't seem concerned so no one bothered bringing it up.

Suddenly left unsupervised, Nagisa made another grab for the petri dishes. Thankfully Makoto was standing by, subtly shifting them out of reach just before Rei came back into the room.

He was pushing another cart, this one laden with a glass case about the size of his tv. At first, it looked like the only thing inside was a wooden log and some sand. It wasn’t until the cart stopped, in full-view of the overhead fluorescents, that he could make out the living creature within.

“Wow, Rei, you’ve been raising lizards!” Came Nagisa’s pleased squeal.

Rei gave him a look, as if he’d just missed something incredibly vital from the lizard-containing glass enclosure. “Not just any lizards, Nagisa. Please observe,” he added this last part to them all, drifting away to find the light switch.

Turning the lights off should have shrouded the room in darkness, but it didn’t, mostly because the glass enclosure was glowing.

That wasn’t strictly true. As Haru inched closer with his friends, he learned that it wasn’t the glass enclosure, but the lizards inside that were glowing.

One was a neon pink, dark stripes on its back coming out a deeper burgundy. The second lizard, about the size of Makoto’s fist, was a deep royal blue, so dark it almost looked like it was underwater. The third and smallest lizard looked like a soft opal, bluish-teal emitting from its ridged skin.

“Rei, this is awesome!” Nagisa was the first to exclaim.

“Yeah, Rei, this is pretty cool,” Makoto congratulated, face awash with filtered colors so close to the tank. His smile was supposed to be supportive, but it quivered on the edges, no doubt due to his general discomfort with all things dark.

Rin’s tell-tale shark teeth made the situation even creepier when they came out with a burgundy tint. “Man, this is amazing. You can’t tell me you’re not gonna graduate with honors, at least. There gonna be a fair? You should totally show ‘em off.”

“Congratulations, Rei.”

Rei was obviously trying not to beam with pride, keeping his smile contained under sheepish embarrassment. “T-thank you, all. You have no idea…” Then, straightening, he finally let loose an emotional grin. “I’m so glad you could be here to see this. Without you all… and the dreams you helped me realize… none of this would be possible.”

Someone might have sniffled, probably Rin. They were distracted from finding out when Rei opened the tank lid and pulled out one of the lizards.

"Is that safe?" Makoto squeaked, hand suddenly gripping Haru's bicep, likely in an attempt to remain grounded.

"Perfectly," Rei assured. "They are merely altered in color. There is nothing dangerous about them."

Nagisa clapped his hands, rushing over to Rei with a laugh, likely about to insist on holding it. Only, in the dark, he knocked into something. Hard.

“Nagisa, are you-“

“Hehe, sorry Rei, guess I’m a little clumsy~”

Rei turned the lights on immediately, face turned down in concern. Nagisa had sounded fine, but he was wincing as he lifted his shirt up.

The thing he'd bumped into was the same table Haru had hit himself on earlier. Only, instead of a little bump, the whole table rocked. Glasses on top tinkled together, and then-

_Crash_

Pretty much everything had stayed in place – everything except for the vials Rin and Haru had been admiring earlier. All three were lying smashed on floor. The glass had broken and scattered in a discolored pile, a mix of ruby liquid and pearl-colored fluid seeping across the beige linoleum.

“Oh no, Rei! Your experiments!” Nagisa wailed, backing away from the table in horror.

“No, Nagisa, those weren’t mine,” Rei muttered, concerned. “In fact, those…”

Before he could finish is mutterings, he let out a strangled yelp. Makoto shrieked, letting go of Haru's arm, and something crashed into him. Whatever it was knocked his center of gravity too far to recover, and without realizing, he was falling to floor.

"Haru!" Makoto cried.

He'd braced his fall, grabbing onto the table with one hand, but as for his knees...

Haru didn't feel the cuts until he tried to stand up, jeans scraping against the open wound in his right leg. It wasn't bad, nothing more than he'd get falling down on the sidewalk, but the added concerns of dangerous chemical exposure sent the rest of his friends through the roof.

“Shit, Nagisa, what the hell’s wrong with you,” Rin snapped, coming around to examine his leg.

"I didn't mean to!" Nagisa wailed, bounding closer to Haruka in fear. "I- I just... the lizard startled me, and I-"

“We need to get that under water,” Rei ordered in a surprisingly calm tone, grabbing Haru's exposed side.

He wasn’t given a chance to move before Makoto was hefting his other arm, the two practically dragging him to the sink. "Hey, wait-"

"Get your pants off," Rei ordered. With a huff and realizing his friends would make him if he didn't, Haru did as he was told.

His jammers were on underneath, much to Makoto's relief. At Rei's insistence, Haru climbed onto the sink ledge with his right leg inside. Quickly the hot water was turned on. The three slices on his knee were already seeping blood, and Makoto didn’t wait before scrubbing soap into them, making the wounds burn even more as they were cleaned with razor-like focus.

The lab wasn’t a biohazard facility; it wouldn’t be that dangerous. Besides, Haru felt fine. There wasn’t even anything on the glass shards he'd landed in. He’d be fine.

Haru’s blasé attitude wasn’t shared by his friends. Nagisa was freaking out, wailing, “But what if that was poisonous!” He continued talking, bemoaning the clumsiness that had gotten both he and Haru injured and probably killed. Because apparently Haru was going to die after being contaminated with some strange virus and he’d need to be rushed to the emergency room and-

Rei, who'd disappeared at some point, returned with a disinfectant spray. Makoto removed Haru’s now-squeaky-clean knee leg from the water so Rei could spray the cuts. “Nagisa, no one has been poisoned. Nothing in this lab is quite so dangerous; at most, he was exposed to a saline solution with reptilian blood samples.”

“Blood samples?!” Makoto shrieked, eyes wide and hands squeezing Haru’s ankle so hard he almost cut off circulation.

“Plasma,” Rei corrected. “But everything in the lab is completely sterile. None of our animals carry diseases, so there is no chance of dangerous infection.”

"So, he'll be okay?" Rin asked. Haru almost jumped at the sudden voice at his shoulder, not having seen Rin come up behind him.

"Yes." Rei patted his knee dry with paper towels. From the first-aid kit that had also appeared at some point, he began wrapping band-aids over the cuts. “Never the less, Haruka, if you feel the slightest symptoms – fever, headache, or anything unusual – report to me immediately. One can never take too many chances.”

He sighed, nervous from all the attention, but forced a nod at Makoto’s still-visible panic.

Once it was determined that Haru wasn’t going to fall on the floor dead, the spill was cleaned. It was decided he'd throw the jeans away in case there was anything on the fabric (and it was too torn to be comfortable), so he ended up borrowing some of Rin's warmups for dinner.

Afterward, Rei checked where Nagisa had injured himself on the table, but the skin was only bruised. Nothing else had fallen, so Rei left a note for his lab mate and muttered something about sending him a text before he went back to the lizards. After the reptiles were secured back in their rooms and the petri dishes were placed in a bench-top incubator, Rei removed his lab coat and all four were herded towards the door.

“Speaking of,” Rei asked, giving the door a confused look, “How did you and Rin manage to get inside my lab, Haruka? I’m pretty sure these keys are-“

“Hey, Rei, come on, I’m hungry! Let’s go celebrate while you tell us more about your discoveries~” Nagisa interrupted, already practically running down the hall toward the elevator.

Rei made a horrified expression. “Wait, Nagisa! No running in the lab building!”

“But Rei, I’m hungry!”

The duo continued to bicker all the way down to the bottom floor. Makoto finally got them to stop when he started questioning Rei about his studies. Rin, instead of leading the way, ended up falling back at Haru’s side. He didn’t say anything, hands in his pockets and ear half-cocked to the conversation a few paces ahead. Makoto kept looking over his shoulder with concerned glances, as if expecting Haru to suffer from some latent exposure and collapse on the spot.

He ignored the both of them, too busy enjoying the cool Tokyo air. The broken glass in the lab was likewise completely forgotten the moment someone had mentioned grilled mackerel.

**Notes for the Chapter:**

> Dun Dun Dun Dun... O_o Rin (I believe) ups the interest for us next chapter.
> 
> P.S. as a side-note, the above situation (rather hypothetical situation, since no one I know researches mermaid transmogrifications) is why you want to know what your other lab mates are researching - always good to know what you've accidentally exposed yourself to. You can never be too safe when it comes to the lab! And yeah, leaving a bunch of stuff you're not using out on the bench like Rei's lab mates did... also not a good idea.


	2. Chapter 2

Rin was busy packing up for his day of training at the pool when he realized his goggles were missing.

It wasn’t a huge deal. He had four pairs and just rooted around in his bag until he found the case the extras were kept in. But he kind of wanted his original pair back, mostly because the new ones were kind of stiff around the plastic and the suction wasn’t as smooth on his skin. 

But… where was he supposed to look? His bag rarely left the natatorium, and even then it went straight to his house, rarely any stops for dinner (since it was cheaper and healthier to cook at home).

Still, the goggle-debacle was quickly eclipsed when he realized what day it was. The day the National Team was holding joint training, where a bunch of them were relegated to the same pool with other coaches.

Today he was swimming with Haru.

Even though they were living in the same city, their individual training schedules made it nearly impossible to join-up as often as he would have liked. Which was probably a good thing, honestly; it saved some of that anticipation for their timed meets. Granted, they didn’t always get sent to the same places, but when they did…

He didn’t want to make a thing of it, but when the two of them raced together, there was always a noticeable difference in his times. Usually Rin could beat his personal best by several seconds. During the races, the two of them always neck-and-neck, whether in adjacent lanes or not.

That feeling, that focus that came with chasing Haru in the water – or being chased by him – was impossible to duplicate. There was nothing like it.

Since it was a joint practice, Mikhail wouldn’t be working with him that day. Instead, he was assigned to one of the team coaches. Rin changed in the locker rooms and stepped into the chlorinated air, eyes immediately panning around for a familiar pair of blue-striped jammers.

He spotted the man in question, standing beside the wall as he fit a pair of goggles onto his face. Rin walked over, trying not to break into a jog before finally coming upon his teammate.

“Hey, Haru.”

“Rin,” he acknowledged. Haru, however, paused before fitting the goggles over his face, glancing at the pool in question.

He grinned, about to slap on his own goggles when a voice froze him in place.

“Matsuoka! What’re you doin’ over there, we got laps to run!”

Ah. Busted.

Slowly, he turned to face his team coach, the one who’d be working with him for the next few days of joint practice. A woman in her mid-thirties, she had a stern expression and a questioning eyebrow that demanded some kind of explanation.

“Um, sorry, Coach, Haru and I were gonna race before we started today.”

“You can race after. I want you starting warm-ups so we can work on your butterfly.”

“Yes, ma’am. Um, Haru, see ya later.”

“Bye, Rin,” he called before slipping into the pool himself, either confident they’d meet up later or more interested in being in the water than hanging around.

Rin didn’t see him again until lunch, almost four hours later. His arms were already starting to feel sore from all the butterfly strokes, making him almost desperate to get a bite in. He was going to track down Haru and make some plans to race later, but the guy wasn’t anywhere in the cafeteria.

Rin was just starting to wonder if he’d stayed in the pool when he spotted a dark head walking towards the door, bag slung over his shoulder.

Rin jumped up, arriving just before Haru got the door open. “Whoa, wait, where are you going?” Was he headed back to the pool? But he was dressed already, so maybe he was going to the gym?

A second coach arrived before Haru could answer. “Nanase isn’t feeling well, so he’s being sent home for the day.”

Rin gave him a look, wanting an explanation from Haru himself. What, did he pull a muscle in training? Was his morning mackerel spoiled?

Haru, however, wasn’t meeting his eyes. And on anyone else, the slight downturn to his lips and hard eyes would look like sulking. “It’s a cold I picked up last night.”

“Last night… you mean you were night-swimming? Again?”

Haru glared at the reprimand, interrupted only by a delicate little sneeze. It would have been kind of cute if Rin weren’t busy being annoyed over his utter lack of concern for his health. Because… really? How many times did he have to get sick after walking around in the cold dripping wet before he learned his lesson?

“Go home, Nanase. Get some rest and text me if you need anything,” the coach commanded, and with one last glance, Haru shouldered his bag and left.

With an eye-roll, Rin went back to lunch. Haru would be better soon. His biggest enemy was himself. Nothing Makoto couldn’t handle.

After lunch was more practice, then some time at the gym. It wasn’t until they were done for the day that he finally unearthed his phone, debating sending a text to Haru. Maybe just to see if he was actually resting or taking some medicine like a good little swimmer. They couldn’t race until he was better, after all, and they hadn’t raced in weeks. What was the point in living so close by if they couldn’t be in the water together whenever they could?

Rin was just about to send a message when he saw a text from Rei.

Speedo Glasses 9:33  
_Hello Rin. I’ve uncovered some  
swimming goggles at my lab that  
I believe belong to you. When would  
be a convenient time to drop them  
off?_

He checked his watch. Actually… the train nearby ran a line to the campus. He could stop by on his way home.

Rin Matsuoka 17:40  
_I’m swimming nearby.  
I’ll come pick them up_

* * *

After showering and changing into warmups and tank top, Rin took the train over.

Much like his visit a few days ago, the campus was fairly empty, late-afternoon sun painting the glass buildings colors of gold and rose. Most of the students were gone because most of the classes were out. The only exception to this was the science building, which was bustling with activity as students freed from coursework flocked to their projects in the lab.

Since Haru had led the way last time (Rin was too busy gawking at the posters and funny gadgets left in the halls) he got lost once and had to ask a passing student for directions. The peppy blonde was very helpful, and after what seemed like miles of hallway, she finally escorted him to the genetics research wing (because apparently that was what it was called). She even pointed out Rei's lab before departing with a wave. The lab, like all the others, was in a hallway full of posters with tiny images and graphs he didn't understand. Thankfully the door had a window that allowed him clear view of the milling lab coats, but because of the gear they wore, it made distinguishing them from each other virtually impossible.

“Can I help you?”

Rin practically jumped, because… Jesus, did they give these scientists sneaky shoes or something? Was it part of some project he didn’t know about – how to make yourself invisible?

The guy who’d approached him had pale, spiky hair, and equally-bleached skin that already gave him a head start in the whole blending-in-with-the-wallpaper idea. The only color came from cerulean eyes that, if possible, looked even colder than Haru’s trademark stare. His young appearance and white coat meant he was probably a student, further verified by the nametag pinned to his lapel.

Rin tampered his glare down, not liking the way this dude was looking at him. “Um, yeah. I’m looking for Spee- er, I mean, Rei Ryugazaki.”

The guy lifted one eyebrow, as if doubting what he was saying before glancing at the door (and really? Who lifted just _one_ eyebrow?). “Mr. Ryugazaki is in the midst of an experiment. I’m sure-“

Rin didn’t get a chance to move before the lab door swung open, blasting him with filtered, cool air. “Ah, Mr. Hamaguchi, I was- Oh, Rin, what are you doing here?” 

The voice did indeed belong to Rei, even if the guy's eyes were obscured by a pair of scratchy eye protectors and his trademark vibrant clothing hid beneath a lab coat. “Um, hi. I sent you a text, about those goggles.”

Rei’s eyes lit up in understanding, but before he could say more, Icicles to their right _tsk_ ed in disdain. “So _he’s_ the one visiting the lab after hours.”

Rei was too calm to wince, but he did straighten at his colleague’s condescending tone. “As you know, Mr. Hamaguchi, guests are not expressly prohibited from the lab space so long as-“

“ _So long as_ they don’t knock over other people’s experiments and set them behind by several months,” he hissed.

So _this_ was the guy who’d created those funny-colored solutions? 

Before Rin could say something anywhere close to an apology, the pasty guy was suddenly in Rei’s face. Even at nose-height, he was intimidating, forcing Rei to jerk back just so they weren’t close enough to rub noses. “If you hadn’t had your _stupid friends_ over, then my assays wouldn’t have-“

“Hey, wait,” Rin snapped. Having dealt with swimmers high on testosterone and even higher on egos, he didn’t hesitate to put an arm between them and shove the new guy back a few steps (which was pretty easy since he was, like, the weight of a toothpick). “It wasn’t Rei’s fault. It was an accident. I’m sorry. Calm down a bit, okay?”

Hamaguchi’s sky eyes met his, and for a moment, Rin froze.

People said Rin was shark-like with his pointed teeth and unique swim style. Normally he shrugged it off with a laugh, secretly pleased people thought enough of him to identify him with one of the most vicious predators in the ocean.

Rin had nothing on this guy.

It wasn’t like the dude had sharp teeth or looked particularly predatory. It was the eyes. It was a look he could never hope to master and wouldn’t want to. This man held a gaze so flat and dead, pale color somehow hardened into a black pit, that Rin felt ice run up his spine. 

He had a sudden flash-back to the first – and last – time he’d seen a gaze like that. It was a few years ago in Australia when he’d come face-to-face with a tiger shark during a scuba dive. He’d run into it on the reef, and the creature was huge. But even more intimidating was the flat expression that met his own. Without pupils, he couldn’t be sure, but he knew the shark was watching him. Waiting for one move that could mean the difference between making it back to shore with some cute fish pictures or not making it back at all.

Then he blinked, and it was gone.

It happened so fast Rin wondered if he’d just imagined it, especially when a completely human voice said, “I’m sorry, I didn’t catch your name.”

His tongue was stuck to the top of his mouth, but managed to bite out, “Rin Matsuoka.”

The scientist raised that stupid single eyebrow, looking more condescending than genuinely interested in the conversation. “Ah, no wonder you looked familiar. You’re the Japanese swimmer from Australia, if I’m not mistaken.”

From anyone else, Rin would have been flattered. Now, he just felt creeped out the guy knew even more about him. “Yeah. That’s right.”

“Indeed. Well, if you’ll excuse me.” He brushed past Rei into the lab without giving either of them a second glance.

Rei stepped out of the doorway before rooting around in his pants pocket, unearthing a pair of navy goggles. “Here, Rin, I apologize for the delay,” he said, handing them over.

“No, it’s fine.” He took the pair, glancing at his friend. The only sign he was bothered by the confrontation was the slight wrinkling between his brows and the distracted shift to his eyes. “Who was that guy, anyway? Does he work in the lab with you?”

Rei let out a sigh, arms crossed and eyes fixed on the far wall. “…Yes. Mr. Hamaguchi is a student in the department like myself.”

“And he’s mad about the vials we smashed.” A nod.

He wanted to ask what kind a stick that guy had up his ass to make him so cranky but didn’t think Rei would appreciate that kind of talk about his colleagues. Instead, he said, “Do you want me to stay after and walk you home? Just in case he gives you any more problems.”

Rei shook his head, eyes flicking to the lab door. “No thank you, Rin. Mr. Hamaguchi is not physically aggressive.”

“Well… okay. I guess I’ll see ya later. Thanks for these,” he added, holding the goggles aloft, scuttling away before he could spout anything else embarrassing.

He was just about to disappear around the corner when a thought occurred to him. Rei was still standing in the hall, and he stopped, turning around with, “You haven’t heard anything from Haru, have you?”

“…Should I?”

“Um, no. Never mind. See ya, man.”

* * *

It wasn’t until two days later and Haru still hadn’t shown up for swim practice that Rin really started getting worried.

He was probably overreacting, he told himself, panning through the water, taking a breath before sinking back into the chlorinated pool. Haru was probably fine. Just a little under the weather from that stupid late-night swimming (a bad idea any time of the year, but even worse when the night temperatures were dropping into the forties). Maybe he’d finally learn his lesson and start staying in doors like he was supposed to.

Mikoshiba and Momo practically dragged him out for drinks and dinner when they were done with practice that day. Rin was too tired to handle the exhaustive ball of energy known as Momotaro Mikoshiba, but he was tired and hungry and Haru still hadn’t gotten back to him. He needed a distraction.

But as if reading his mind, Mikoshiba scrubbed a hand through his spiky hair before saying, “Hey, have you heard anything from Haru lately? I’m kinda worried, seein’ as he hasn’t shown up for practice in a few days.”

 _You and me both,_ he thought but didn’t say. Swallowing a bite of steak, he leaned back in his chair. “Coach said he’s sick.”

“Man, that’s too bad. I know he was looking forward to swimming with you.”

Rin jerked up, meeting a pair of tired golden eyes. “Really?”

A shrug. “Well, yeah, isn’t he always? You two are somethin’ else in the water.”

Momo popped up from the mess he was making of some noodle dish, slurping two strands into his mouth with zeal. “Hells yeah! Who wouldn’t want to watch that race? You two are epic in the water. Hey, Bro, can I come to practice next time? I heard there’s some ladies who’ve been hanging out to…”

And Momo descended into babble that Rin tuned out automatically. It became easier when a text alert came in on his phone.

He slid the device from his pocket, only for a pit of dread to form in his stomach at the message.

Makoto 19:54  
_Rin, have you heard from Haru?_

After excusing himself from the table, he drifted to a quiet corner by the windows before hitting _Call_.

“Hey, I got your message. What’s up?”

Makoto, obviously a little surprised he’d actually called, let out a flustered breath. “Um, well, I haven’t heard from Haru and a few days, and I just wondered if you’d seen him at practice.”

“…No, I haven’t.”

Makoto kept talking as if Rin hadn’t spoken. “I know he said he was sick with a cold, but when I saw him yesterday, he seemed fine, just very tired. I was kind of hoping he’d recovered overnight, but…”

“You saw him?”

“Yeah, I dropped by after work, but I can’t come by tonight.” A pause and some shuffling on the other end. “It’s just… after what happened at Rei’s lab the other day, I guess I’m a little worried.” Then, he chuckled. It sounded forced. “It’s kind of stupid, right? I’m sure he’s fine.”

“Wait, you mean… the broken glass he cut himself on? Makoto, Haru’s just got a little cold. You’re overreacting.”

“Yeah, probably. I’m sure he’s fine. Thanks, Rin, and I’m sorry to bother you.”

Makoto hung up before he could say anything else.

But it was too late – Rin’s mind was already whirring with concern. Which was… stupid. There was no way Haru had contracted some mutant virus or anything. The guy was fine, probably just being a baby about his cold and using the excuse to get out of dry-land work. Makoto was completely overreacting.

And yet, when dinner was over, Rin found himself following Mikoshiba and Momo to the train station instead of huffing it to his apartment a few blocks away. They didn't have a chance for a long goodbye before he was boarding the train that would take him to the northern end of Tokyo. Rin hardly noticed when the train actually pulled out, too busy trying to remember the right stop for Haru’s district.

**Notes for the Chapter:**

> Ok, I know I said Rin would liven it up, but setting the stage took like 5x longer than I thought. Apologies - the truth will be revealed in due time (and I posted this chap way earlier than I planned because I had the time; others won't be as rapid).


	3. Chapter 3

**Notes for the Chapter:**

> I know I said I'd post later but I changed my mind. Rin's reactions are strangely motivating.

Unlike Iwatobi this time of year, Tokyo was still relatively warm. Too warm for snow, but not so warm that the breeze didn’t carry a distinct bite, Rin zipping his hoody up and shoving his hands inside the pockets as he trudged from the station. The side of town where Haru lived was quieter than his own, further from downtown. Haru’s apartment complex was mostly dark by the time he got there, only a handful of lights still on. It was a beacon in an otherwise dark suburb, the park and local natatorium dark and vacant. 

Rin scowled, white air puffing before him as he stalked up the building steps, metal clanking beneath him.

Stupid Haru. Couldn’t have just answered the phone like a normal person. Couldn’t have saved him the trip out at eight in the evening, running the risk of missing any trains back to his side of town. Oh, no. He had to be a baby about some silly winter cold and give Makoto a scare. No thanks to Nagisa’s cries of mutant viruses and deadly poisons, now ringing around in Rin’s head like wind chimes.

He hit the landing with a bang. A quick jog and he was standing at the end of the hall, right outside the apartment with _Nanase_ printed in neat Kanji beside the door.

He rang the bell once. Twice. Thrice.

Rin tapped his feet, shifting to try to keep warm. Gave it a few seconds.

_Bang Bang Bang_

“Haru! Open the door! You better be dyin’ or worse. Makoto’s so worried he almost skipped work to come check on you. Open this door, or I swear to god I’ll wake the super and-“

He heard the latch flip, expecting the door to open. But it wasn’t Haru’s. Instead, it was the neighbor’s – an old woman ranging anywhere in age from fifty to eighty gave him a nasty glare over her pince-nez.

“Young man,” she hissed. “Please keep it down. Some of us are trying to sleep!”

Rin resisted the urge to wince and start apologizing. It went against every instinct beat into him by his mother and Lori when he flat-out ignored her and turned back to Haru’s door, still shouting. “Oi, Haru! Even your neighbors are awake. I’ll stay here until the whole building’s up if you don’t get off your ass and let me in. Unless you want to keep-“

The door opened.

After all the worrying from Makoto, Rin almost expected Haru to be half-covered in some weird black spores and missing a limb.

It was almost disappointing that Haru was completely fine.

Even backlit by the foyer light, his eyes didn’t look puffy, his nose wasn’t running, and his breathing wasn’t labored. The only thing odd about him was the robe he was wearing. Not so much because he was wearing it, but because Rin didn’t even know he had one – the man would rather lounge around in jammers or nothing at all instead of a cloth wrap-around.

Rin was relieved – a little – at his friend’s living state. He managed to mask it, however, by the utter frustration and anger at having hauled his ass halfway across Tokyo just to find out Haru was throwing another one of his anti-gym tantrums.

“What the fuck?! You’re obviously fine. Would it have killed you to pick up the damned phone instead of- wait, hey!”

Before he could stop it, Haru wrapped a hand around his lapels and yanked him inside, apartment door slamming shut in his wake.

“What the hell’s wrong with you? You could have just invited me in like- hey, where are you going?”

Haru didn’t answer, just turned in his royal-blue bath robe and continued into his apartment. Rin muttered a swear word before yanking his shoes off, understanding this was probably going to be a long visit (since nothing with Haru was ever easy and usually took longer than his patience ever allowed). Rin kept his jacket on because the place was so cold, as if Haru hadn’t run the heater all day. 

The apartment was still as spick-and-span as every other time he’d been by, the couch arranged, single blanket folded over the back, kitchen appliances tucked away with the kettle left out. The familiar dark head had disappeared, and it was only once he spotted the bathroom door open with the light on that Rin rolled his eyes.

“If you dragged me in here just to watch you take a soak, we’re…”

His voice trailed off as soon as he stepped inside. Not because he’d run out of things to say, but because he was too frozen in shock to even remember what he was talking about.

Haru had jumped in the bathtub while he’d been busy in the foyer. And while his delicate areas were obscured by a speedo (also a new addition to Haru’s wardrobe), Rin’s eyes were focused not on the strange choice in swimwear, but on Haru’s legs dangling over the side of the tub.

Or more specifically, the scales.

Rin spent several undignified seconds with his mouth hanging open, taking in the glimmering flecks that peppered his legs. Topaz flakes dotting his skin like random spots on a dog, starting at the skin just beneath his speedo to the ankles braced on the wooden edge. They weren’t enough to cover, but enough to draw attention, varying in size and location. 

When he finally managed to close his mouth, he glanced up at his friend. Haru was watching him from his place at the head of the tub, arms half-holding his shoulders out of the water, face arranged in an impassive mask.

“I guess this is why you weren’t at practice today?” It was a stupid question, and pretty tame compared to the jumble of others already swirling around in his brain. Haru’s glare seemed to say as much.

Without thinking, he placed a finger over a scale on Haru’s right femur. It was hard and seemed sharp, like the ones found on any other fish, but larger. The skin beneath them almost looked… inflamed, puffed up and shiny, thick layers of epithelials rushing up to meet the glittering flakes.

“When did this start?”

Sapphire eyes met his before flicking away. “…The scales showed up this morning.”

Rin still hand a finger along some of the unusually firm skin when he looked up, understanding what Haru wasn’t saying. “The scales… you mean there’s more?” 

Haru, instead of answering, opted to glare at the wall.

“Oi, Haru.”

He finally looked over, still glaring. “My legs hurt. And things have been… shrinking.”

“Shrinking? What do you mean?”

Haru’s cheeks might have been a little red but it was hard to tell in the half-lit room. He gestured to the bath water, and because of his vagueness, it took a few seconds for Rin to catch on.

“You mean- you mean _that_?” He got up to take a look, peering down at the navy speedo.

“Rin!” Haru snapped, instinctively drawing his legs up for cover. 

Realizing what he’d been about to do, Rin’s face got as red as his air, embarrassment poorly masked with a scowl. “Okay, sorry.” As a distraction, he pulled the bathing stool over, wood legs screeching on the tile before coming to rest by Haru’s ankles. “So, what exactly’s going on? This started… a couple days ago, right?”

Haru nodded. He tried to draw his legs closer, only to wince and extend them back out.

“Does it… do you think it has something to do with what you cut yourself on in Rei’s lab?”

Haru’s eyes were flat. “I don’t think it’s a winter cold,” he deadpanned.

Rin scowled, cheeks warming some in embarrassment. “I’m just trying to help you. You’re the one that dragged me in here.”

He saw Haru try to move around again, wincing when his legs laid a certain way. With an eye-roll, Rin rose and left the bathroom. He found Ibuprofen next to vitamins in the kitchen cabinets, stopping off at the sink for a glass of water before crossing back to the bathroom.

“How helpless are you,” he accused, thrusting the pills and the glass into Haru’s water-logged hands.

His friend rolled his eyes but didn’t look particularly irritated as he downed the blue ovals. “I’m not helpless. I took them earlier today.”

“You’re not overdosing, are you?”

“No. It was five... six hours ago,” he verified, glancing at the dial clock nailed into the wall, then swallowed both pills in one gulp.

“Have you talked to Rei?”

He shook his head. Rin had his phone out and dialing before Haru explained, “Nagisa told me he has some science conference in Sydney. He left this morning, and I think he’s still on the plane.”

He swore, because really? Couldn’t one thing go right?

Sure enough, it went straight to voicemail. Rin left a quick message conveying the urgency but not leaving any details before hanging up. 

“Can you walk?” he asked, pocketing his phone.

“Yes.”

“Then let’s go. We’re taking you to the hospital.”

“No.”

Rin was already standing and looking around for some car keys when Haru’s denial finally penetrated. “’No’? What do you mean, ‘no’? Haru, you’ve got weird scales on your legs and… whatever else is going on down there. We’ve got to get you some help.”

“I’m not going there just so they can just poke and prod at me.”

“And if you don’t?”

Haru held his gaze without looking away. “Rei knows what he’s doing. He knows a lot more about this than some scientist in a hospital. Aside from the scales, I’m fine, so-“

Rin’s phone started ringing and he didn’t bother waiting for Haru to finish before answering.

Rei’s voice was overloud against his ear. “Rin, I just got your message! I’m sorry for missing your call, but I’m in Sydney, Australia, in case you hadn’t heard. Your original stomping grounds! Aside from some jet-lag, I’m actually enjoying-“

“Oi. Speedo-glasses. Shut up for a minute. Are you near a laptop?”

“Um, yes, I just got into my hotel room, but-“

“Log onto skype. There’s- no, never mind, just log on. I need to video call you.”

Even with a cryptic order like that, Rei didn’t ask any questions; the sound of the phone clacking against a tabletop was heard, followed by the muffled noises of zippers pulling and a laptop powering on.

“Is everyone alright?” He finally questioned, probably waiting for his software to open up. “No one was injured, where they? Is it something in the lab?”

“Everyone’s fine.” _Sort of._ “Haru’s got somethin’ to show you,” he explained, meeting the eyes of his soaking friend. “It… kinda has to do with our lab visit last week.”

The rapid typing noises suddenly ceased. “Haruka?! Is he alright?! What happened?!”

Rin tried not to wince at the sudden increase in volume. “Just… open up skype, okay? The call’s gonna drop but give me a few minutes to get the app open on my phone.”

Rei wasn’t given a chance to agree with the plan before Rin hung-up on him, opening his skype app and logging in. He had Rei’s contact in there for some reason, and the scientist picked up before the ring could completely sound.

Even through a laptop, Rei was leaning so far forward in his chair that all Rin could see was the top-half of his face, lavender eyes and ruby glasses the only points of color.

“Hi, Rei. I’m gonna switch the camera so you can see what I’m talking about.”

He did just that, making sure the camera was working before giving Rei a good view of the new additions to Haru’s legs.

When their friend didn’t say anything for almost a whole minute, Rin started to wonder if he’d accidentally muted the call. Only, he didn’t, and when he’d switched the camera back around, Rei was sitting back from the computer, staring at the screen in a daze (or maybe he’d fallen asleep – it was hard to tell the difference with the poor pixelation).

“So?” Rin prompted when it was clear he wasn’t going to say anything. “How do we fix this?”

Rei started at his voice, eyes losing some of their lost-in-space luster. “This is… unexpected.”

Rin clenched his teeth, arms crossed. “Yeah, no shit. How do we fix it?”

Instead of answering, Rei adjusted his lenses. “I had… but… something like this…”

“What?” Rin asked, unable to make out the unintelligible mumbling.

Rei frowned in concentration, gaze transfixed on his own screen. His face was in shadow thanks to the lampshade behind him, the sole light in the otherwise dark room. “…I suspect something has altered Haru’s physiology on a genetic level.”

“No shit,” he snapped, patience already growing thin.

“Is it from the stuff I cut myself on in the lab?” Haru asked.

“Was that Haruka?” Rei called, peering closer at the screen as if hoping to catch a glimpse of his friend.

Rin pulled the bath stool over by Haru’s shoulder. He sat down so they two of them were in the camera frame, his frowning face a sharp contrast to Haru’s hardened mask.

“Ah, Haru, hello.” Rei adjusted his lenses, as if buying time to think. “My first response would be ‘no’, since my lab doesn’t work on any chemicals or synthetic solutions with transformative effects.”

Even though the last part of his statement was a little confusing to Rin, he understood ‘no’ well enough. “But your lab is in the genetics department. This has to be related.”

“You haven’t been to any other labs on campus, have you, Haruka?” Rei asked. Haru didn’t even have to shake his head, the expression on his face already conveying an irritated _no_.

“So it had to be from your lab, right?” Rin snapped, annoyed that he had to keep repeating himself.

“You don’t understand,” Rei explained, and, yeah, nothing new there, “usually it’s only possible to alter a genome before birth, not after an organism has grown, like with Haruka. And scales? This is impossible. My lab simply doesn’t work with that kind of advanced genetic technology. The only way to do it would be…” Rei stopped talking, like someone had hit the STOP button on his brain. It went back into motion when he scowled, almost breathing the name, “Kaito Hamaguchi.”

“…The guy from your lab?” He asked, name bringing up an image of a blue-eyed pale guy.

“He works with fish. He must have found some way to combine Dr. Kale’s research in lizard limb regrowth with- yes, the scales! They’ve been using _Chromis Cyanea_ as model organisms. No doubt that’s where the unique coloring comes from, although combining the genes to allow limb regrowth, much less limb transformation, would take the use of superior skills that he could only get through collaboration. However, the risk of degradation to genetic structures for-“

“Rei,” Haru snapped, cutting him off mid-rant and drawing their attention to him. He was sitting half out of the tub, gaze fixed on the phone screen. “What’s happening to me? Is it permanent?”

The scientist in question adjusted his glasses, buying time as he put together an answer. “I… don’t know.” 

He didn’t _know_?

Before Rin could snap just that, Rei rushed to explain, “If you were exposed to what I think you were, then this should be reversible. As to what’s happening…” He glanced away, lips pursed, shuffling through some papers just on the edge of the screen. “I believe you’re exhibiting the early signs of organ regrowth.”

“Organ what-now?” Rin snapped, patience wearing thin with all the technical lingo.

“I believe your body is changing to display some form of recombined human and _Chromis Cyanea_ genes. Without knowing specifically what was recombined, I don’t know how much or how little of the genome was incorporated into your cellular makeup. Those few scales could be all, or within the next week you could grow fins and develop a two-chambered heart. There’s no way as yet to be certain.”

“…I don’t know what that means,” Haru said.

“Pretend like you’re explaining this to a bunch of kids with arts degrees,” Rin grit out, knowing Rei-Speak was a lost cause for anyone without a Ph.D. in the sciences or linguistics.

Rei let out a heavy, put-upon sigh before managing to do as instructed. “To put it simply and without the qualifications deserving… Haru is changing into a fish.”

Okay. Never mind. That wasn’t any less confusing than the first story. “I’m sorry.”

“Not a true fish, you understand, but it appears that parts of his cell- mm, I mean, parts of his _appearance_ are changing into _fish_ parts.” Then, at the horrified looks on their faces, he held up his hands in supplication. “There’s no need to panic – the scales might be the only thing he grows. I won’t know just how much fish physiology he’s incorporated until I examine samples.”

“…And you’re saying _fish genes_ are responsible for this?”

“Not exactly, but… if I cut aside the additional lingo, then yes, you could say that.”

Rin scrubbed a hand through his hair, violently shaking the screen with the movement. He was trying to keep his cool, but it was growing harder and harder the more this conversation drug on. “You said you needed samples. How soon can you come over and get them?”

Purple eyes glanced around his hotel room, Rei barely stifling a yawn. “I’m going to be here for another five days, unfortunately, so this will have to wait.”

Wait, _what_? Five days?! Was he saying they’d have to wait almost an entire _week_ before he could even _begin_ to look at the problem?!

“Cut your trip short!” he demanded. “Haru can’t swim until this is taken care of, and we’ve got Olympic trials in a few months. He’s got to train, and-“

“I apologize, Rin, but this technology is advanced. Even when I get back, it will take me at least _another_ week to root through Kaito’s notes before I can fully understand what Haruka has been exposed to.” Some shuffling papers on the other end before a notebook appeared on the screen. “I will do some advanced reading from here, of course, but until I have his notes and can see what he’s already done in the lab, there is nothing much I can do.”

“So… weeks. Weeks before this is going to be fixed.”

Some of Rin’s ire was tempered by the disappointment in Rei’s pixelated image. “Yes. I’m sorry, Haruka.”

Whatever. Rin stood up, passing the phone off to Haru before zipping up his jacket. “I’m taking you to a hospital. Where’s your robe?”

“I’m not going.”

“I’m not sure that’s a good idea.”

They both spoke simultaneously, Haru clutching the bath lip as if worried Rin would yank him out by force. “Why the hell not?”

He wasn’t sure exactly who he was asking, gaze flitting between the two, and Rei answered, “I can assure you, there’s nothing they can do for him at this point. This technology is advanced. At best, they would put him in a hospital room on IVs and attempt treatments for the symptoms, not fix the overall problem. And at worst…” A quirked eyebrow. “I don’t suppose you’ve ever seen _E.T._?”

 _Well, shit._ “Okay, then what? Do we just wait for you to get home and hope for the best?”

“Can we talk to this guy?” Haru asked, jaw clenched and eyes hard. “The scientist you said came up with this.”

“…not exactly. Kaito is obviously keeping this a secret from my lab and he would not be willing to divulge a solution to us. If anything, he would be the most likely to lock you in a tank for observation.”

Of course he would. Rin had only met the guy once, yet he didn’t have a hard time believing that at all. “So… we’re just supposed to sit here and wait until you come back.”

Rei nodded, missing the sarcasm entirely. “It would be best if someone could stay by Haru’s side in case complications arise. When I return, I’ll look at Kaito’s notes and evaluate the best course of action.” There was a knock on what sounded like Rei’s room door. His eyes widened in concern, gaze flicking down to his thin watch. “I will do what research I can from here, but please be careful in the meantime. Keep a close eye on your condition and contact me with the slightest change.”

The screen went dark.

It was a few moments of stunned silence before Rin took the phone back, trying not to chuck it in the process. “Well, that was a complete waste of time.”

He looked back, expecting some kind of silent agreement from his friend, but Haru wasn’t even paying attention. His eyes were fixed on the bathwater, looking typically blank. Behind his sapphire eyes, Rin could swear there was a glitter of frustration, and… maybe even a little fear? It was enough to tamper his own frustration and swallow whatever other complaints he was about to launch. Obviously there was some emotion Haru was bottling up, and even though Rin wasn't familiar enough in the silent language of Haru's face to identify what it was, he had a good guess.

Hell, Rin knew if someone told him his body was about to turn into a fish, he’d probably be in tears. Haru hadn’t even raised his voice.

Rin sat back down on the stool with a weird pain in his chest. “Hey.” When Haru didn’t acknowledge him, Rin eyed the hand resting on the rim of the tub. He hesitated, glancing at Haru one last time before deciding _fuck it_ and placing his own over Haru’s.

His skin was damp, but also cold. Colder than it should be from sitting in the bath water for the past half hour. Had he been in here all day?

Haru finally looked up, fingers twitching beneath his own. “We’ll figure something out. Rei’s smart. He’ll know what to do.”

 _Assuming he comes back in time,_ Haru didn’t have to say.

Rin didn’t have an answer, so he squeezed the fingers under his grasp. “Do you want me to help you to bed?”

The huffy glare told him enough. “I can do it.”

“Then, do you have any spare futons?”

Haru, in the midst of extracting himself from the bath water, stopped. “…You’re staying?”

“Yeah.” For some reason, Rin felt a little self-conscious. He managed to keep it from showing on his face, holding Haru’s stony gaze. “Rei said someone should stay with you, right? To make sure nothing changes.”

He didn’t realize he still held Haru’s hand until he drew it away to drain the tub. “I don’t have one.”

“Why not?”

“I don’t get cold and no one stays over anymore.”

Made sense. “Okay, so… I’ll just take the couch.”

Haru didn’t say anything before disappearing out the door, a trail of dripping water left in his wake.

_Couch it is._


End file.
